Parallelism in eyewitness and mock witness identifications

The fairness of eyewitness identification lineups is assessed through the u se of a series of fairness measures. All the measures proposed to date are based on the lineup choices of 'mock witnesses'. Mock witnesses an persons who have not previously seen the offender but who have been given informati on about him, usually a verbal description. In a fair lineup mock witness c hoices should be distributed approximately equally across all lineup member s. Simultaneous presentation of lineup members is the most common form of i dentification procedure, although recent evidence suggests that sequential presentation decreases the proportion of false identifications while mainta ining the proportion of correct identifications. The present study used lin eups from a recent court case to explore the limits of the mock witness par adigm using different photographs of the defendant, variations in the verba l description, and two presentation modes. Results indicated that suspect c hoices and the distribution of foil choices were sensitive to changes in th e suspect photograph and alternate forms of the verbal description. The pat terns of mock witness choices were similar across presentation modes. Our f indings raise questions concerning the limits of the validity of the mock w itness paradigm. Specifically, they illuminate the cognitive process differ ences between eyewitnesses and mock witnesses, and the information availabl e for the identification decision. Copyright (C) 1999 John Wiley & Sons, Lt d.